I am thinking that I should simply make a very simple notch filter
that suppresses the spurious line by 10 or 20 dB. I can then do
an A/B comparison of the measured ADEV with and without the filter.
If there is no change, I'm done. Otherwise, I add filtering in
steps until the ADEV reaches an
Surely all that's required is a simplistic worst case analysis.
Just assume that the value of Tau is always the worst possible so the full
effect of the modulation is always seen.
If the worst case phase modulation is say phi
then the worst case ADEV (Tau) will be proportional to phi*T/Tau
One might also do some trials based on comparing ADEV results between a
clean carrier signal
and ones corrupted with varying degrees of FM (for example), to get a feel
for the problem. If
nothing else, one ought to be able to get some feel for the sensitivities
involved.
Dana K8YUM
On Mon,
On 8/5/18 11:22 PM, Poul-Henning Kamp wrote:
In message <84a802ff-88f1-5f50-1f79-71d8ba3c4...@rubidium.dyndns.org>, Magnus D
anielson writes:
What does exists is a formula for how a single sine spur would produce
ADEV. A FM deviation with low enough modulation index creates two
In message <84a802ff-88f1-5f50-1f79-71d8ba3c4...@rubidium.dyndns.org>, Magnus D
anielson writes:
>What does exists is a formula for how a single sine spur would produce
>ADEV. A FM deviation with low enough modulation index creates two
>side-bands of opposite sign but same amplitude.
I
Hi Rick,
On 08/06/2018 07:12 AM, Richard (Rick) Karlquist wrote:
> I need to measure ADEV on a source that has spurious
> sine wave frequency modulation on it. I am looking for a
> formula that would tell me ADEV, vs FM deviation and
> carrier frequency. I'm not sure if modulation frequency
> or
